U.S. patent application number 16/943430 was filed with the patent office on 2022-02-03 for lifting device for a wind turbine rotor blade.
The applicant listed for this patent is General Electric Company. Invention is credited to Joseph Lawrence Chacon, Ravi Chandra Kamarajugadda, Ulrich Werner Neumann, Emily Jacob Palmer, Molly Christine Stieber.
Application Number | 20220034302 16/943430 |
Document ID | / |
Family ID | |
Filed Date | 2022-02-03 |
United States Patent
Application |
20220034302 |
Kind Code |
A1 |
Neumann; Ulrich Werner ; et
al. |
February 3, 2022 |
LIFTING DEVICE FOR A WIND TURBINE ROTOR BLADE
Abstract
A lift system for a rotor blade of a wind turbine includes a
lifting device having a structural frame body having a root end and
a tip end. The root end supports a root cradle and the tip end
supports a tip cradle. The root and tip cradles each have a profile
that corresponds to at least one exterior surface of the rotor
blade so as to receive and support at least a portion of the rotor
blade. Due to a shape of the rotor blade, when the rotor blade is
installed in the lifting device and lifted uptower, the rotor blade
can experience an asymmetric loading. Accordingly, the lift system
also includes a variable airflow assembly coupled to tip end of the
lifting device. The variable airflow assembly includes at least one
surface moveable between a plurality of positions having varying
resistances so as to counteract the asymmetric loading.
Inventors: |
Neumann; Ulrich Werner;
(Simpsonville, SC) ; Stieber; Molly Christine;
(Schenectady, NY) ; Palmer; Emily Jacob; (Chicago,
IL) ; Chacon; Joseph Lawrence; (Greenville, SC)
; Kamarajugadda; Ravi Chandra; (Bangalore, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Appl. No.: |
16/943430 |
Filed: |
July 30, 2020 |
International
Class: |
F03D 13/10 20060101
F03D013/10; B66C 13/08 20060101 B66C013/08; B66C 1/10 20060101
B66C001/10; B66C 13/06 20060101 B66C013/06; B66C 13/16 20060101
B66C013/16 |
Claims
1. A lift system for a rotor blade of a wind turbine, the lift
system comprising: a lifting device comprising a structural frame
body having a root end and a tip end, the root end supporting a
root cradle, the tip end supporting a tip cradle, the root and tip
cradles each comprising a profile that corresponds to at least one
exterior surface of the rotor blade so as to receive and support at
least a portion of the rotor blade, wherein, when the rotor blade
is installed in the lifting device and lifted uptower, the rotor
blade experiences an asymmetric loading; and, a variable airflow
assembly coupled to tip end of the lifting device, the variable
airflow assembly comprising at least one surface moveable between a
plurality of positions having varying resistances so as to
counteract the asymmetric loading.
2. The lift system of claim 1, wherein the plurality of positions
comprise, at least, a first position and a second position.
3. The lift system of claim 2, wherein the at least one surface is
one of a plurality of surfaces mounted to a frame member, the first
position being synonymous with the plurality of surfaces being in
an open position with respect to the frame member and the second
position being synonymous with the plurality of surfaces being in a
closed position with respect to the frame member, wherein the open
position provides a first resistance with respect to the asymmetric
loading and the closed position provides a second resistance with
respect to the asymmetric loading, the second resistance being
greater than the first resistance.
4. The lift system of claim 2, wherein the at least one surface is
secured to a hinge point, the first position being synonymous with
the at least one surface being in a compressed position and the
second position being synonymous with the at least one surface
being in an expanded position from the hinge point, wherein the
compressed position provides a first resistance with respect to the
asymmetric loading and the expanded position provides a second
resistance with respect to the asymmetric loading, the second
resistance being greater than the first resistance.
5. The lift system of claim 1, wherein the variable airflow
assembly is moveably coupled to tip end of the lifting device such
that the variable airflow assembly can be moved to a hidden
position with respect to the structural frame body to minimize an
impact of the variable airflow assembly after the rotor blade has
been installed uptower.
6. The lift system of claim 1, further comprising a gyroscope
assembly comprising at least one gyroscope configured to modify an
orientation of the lifting device as the lifting device is lifted
or lowered to and from a hub mounted to a tower of the wind
turbine.
7. The lift system of claim 6, wherein the at least one gyroscope
comprises a first gyroscope and a second gyroscope, the first and
second gyroscopes being coupled to at least one of the root and the
tip ends of the structural frame body, respectively, or at an
intermediate location along the structural frame body.
8. The lift system of claim 6, further comprising a drive mechanism
for driving at least one of the variable airflow assembly or the
gyroscope assembly, the drive mechanism comprising at least one of
a generator, an integrated motor, or a separate motor.
9. The lift system of claim 8, further comprising a controller
configured to control the drive mechanism of the at least one of
the variable airflow assembly or the gyroscope assembly.
10. The lift system of claim 8, wherein, when power is lost or an
emergency stop is initiated, the controller is configured to
operate in a failsafe mode in which at least one of a speed of the
at least one gyroscope, a tilt of the at least one gyroscope, or a
position of the surface are controlled to a predetermined safety
threshold.
11. The lift system of claim 9, wherein the controller comprises at
least one of a remote control, a turbine controller of the wind
turbine, or a separate controller from the wind turbine.
12. The lift system of claim 9, further comprising one or more
sensors communicatively coupled to the controller for monitoring
the orientation of the lifting device as the lifting device is
lifted or lowered to and from the hub mounted to the tower, wherein
the one or more sensors comprise at least one of Global Positioning
Sensor (GPS) sensors, accelerometers, smart sensors, or
combinations thereof.
13. A method for controlling orientation of a lifting device for a
rotor blade of a wind turbine as the lifting device is lifted or
lowered to and from a hub mounted to a tower of the wind turbine,
the method comprising: securing a variable airflow assembly to a
tip end of a structural frame body of the lifting device, the
structural frame body supporting a root cradle and a tip cradle,
the variable airflow assembly comprising at least one surface
operable between a plurality of positions with varying resistances
so as to counteract an asymmetric loading of the lifting device;
securing the rotor blade atop the root and tip cradles of the
lifting device; and, lifting or lowering the lifting device between
a ground location and the hub while altering between the plurality
of positions of the at least one surface to counteract the
asymmetric loading.
14. The method of claim 13, wherein the at least one surface is one
of a plurality of surfaces mounted to a frame member, the first
position being synonymous with the plurality of surfaces being in
an open position with respect to the frame member and the second
position being synonymous with the plurality of surfaces being in a
closed position with respect to the frame member, wherein the open
position provides a first resistance with respect to the asymmetric
loading and the closed position provides a second resistance with
respect to the asymmetric loading, the second resistance being
greater than the first resistance.
15. The method of claim 13, wherein the at least one surface is
secured to a hinge point, the first position being synonymous with
the at least one surface being in a compressed position and the
second position being synonymous with the at least one surface
being in an expanded position from the hinge point, wherein the
compressed position provides a first resistance with respect to the
asymmetric loading and the expanded position provides a second
resistance with respect to the asymmetric loading, the second
resistance being greater than the first resistance.
16. The method of claim 13, further comprising moving the variable
airflow assembly to a hidden position with respect to the
structural frame body to minimize an impact of the variable airflow
assembly after the rotor blade has been removed from the lifting
device.
17. The method of claim 16, wherein moving the variable airflow
assembly to the hidden position comprises at least one of folding
the variable airflow assembly against the structure frame body,
sliding the variable airflow assembly towards a center location of
the structural frame body, compressing the variable airflow
assembly, or receiving the variable airflow assembly within a
recess of the structural frame body.
18. The method of claim 13, further comprising: coupling a
gyroscope assembly having at least one gyroscope to the lifting
device; and, fine tuning the orientation of the lifting device as
the lifting device is installed onto the hub mounted to the tower
of the wind turbine.
19. The method of claim 13, further comprising automatically
controlling, via a processor of a controller, at least one of the
variable airflow assembly or the gyroscope assembly so as to modify
the orientation of the lifting device as the lifting device is
lifted or lowered to and from the hub mounted to the tower.
20. The method of claim 13, wherein, when power is lost or an
emergency stop is initiated, operating, via the controller, at
least one of the variable airflow assembly or the gyroscope
assembly in a failsafe mode in which at least one of a speed of the
at least one gyroscope, a tilt of the at least one gyroscope, or a
position of the surface are controlled to a predetermined safety
threshold.
Description
FIELD
[0001] The present disclosure relates in general to wind turbines,
and more particularly to lifting devices for wind turbine rotor
blades.
BACKGROUND
[0002] Wind power is considered one of the cleanest, most
environmentally friendly energy sources presently available, and
wind turbines have gained increased attention in this regard. A
modern wind turbine typically includes a tower, a generator, a
gearbox, a nacelle, and one or more rotor blades. The rotor blades
capture kinetic energy of wind using known airfoil principles. The
rotor blades transmit the kinetic energy in the form of rotational
energy so as to turn a shaft coupling the rotor blades to a
gearbox, or if a gearbox is not used, directly to the generator.
The generator then converts the mechanical energy to electrical
energy that may be deployed to a utility grid.
[0003] The typical construction of a wind turbine involves erecting
the tower and then connecting various other components to the
erected tower. For example, the rotor blades may be lifted to an
appropriate height and connected to the tower after erection of the
tower. In some cases, each of the rotor blades is connected to a
hub before lifting, and the connected rotor blades and hub are then
lifted and connected to the tower as a unit. Trends towards taller
towers and larger rotor diameters, however, can limit and/or
preclude lifting such units to the tower due to size and/or cost.
More specifically, as the rotor diameter and/or mass and hub height
increases, there are few (if any) cranes that can lift such
structures. Further, the sail area can become so large, that the
available wind window to conduct such lifts approaches zero, i.e.
the cranes cannot lift the rotor without tipping over.
[0004] Thus, current systems and methods for lifting the rotor
blades involve lifting each rotor blade uptower individually using,
for example, a cradle, sling, or clamping-type blade lifting tool
that is lifted using a crane. Individual rotor blades can then be
connected to the hub.
[0005] When installing the blades individually using such a lifting
tool, the center of gravity of the blade has to be located under
the crane hook for it to remain stable and hang balanced. However,
due to the asymmetrical nature of wind turbine rotor blades, the
center of gravity thereof is not at its center. More particularly,
when the blade is positioned in the lifting device properly, there
will be a short but very large diameter root section on one side of
the tool and a very long but aerodynamically shaped section on the
other side, thereby causing the asymmetric load. When exposed to an
even wind flow, the root section will create a higher resistance
than the long blade section on the tip side, despite the fact that
it is much shorter. In simple terms, the root section has a higher
drag coefficient and therefore creates a greater drag force than
the tip of the blade. This imbalance causes rotation of the entire
system.
[0006] Therefore, conventional systems utilize one or more tag
lines connected to the lifting tool that can be held by an operator
on the ground as a rotor blade is lifted uptower. As the rotor
blade is lifted, however, control of the load via the tag line(s)
becomes less effective. More specifically, the operator has to
apply more and more force to the tag line(s) as the load is lifted
with less results. In addition, due to the shape of the rotor blade
(i.e. a thick, round root end that tapers to a long, slender tip
end), the blade can experience asymmetric loading (e.g. due to the
incoming wind) as it is lifted uptower.
[0007] In view of the aforementioned, an improved lifting device
for lifting wind turbine rotor blades uptower is desired in the
art.
BRIEF DESCRIPTION
[0008] Aspects and advantages of the disclosure will be set forth
in part in the following description, or may be obvious from the
description, or may be learned through practice of the
disclosure.
[0009] In one aspect, the present disclosure is directed to a lift
system for a rotor blade of a wind turbine. The lift system
includes a lifting device having a structural frame body having a
root end and a tip end. The root end supports a root cradle and the
tip end supports a tip cradle. The root and tip cradles each have a
profile that corresponds to at least one exterior surface of the
rotor blade so as to receive and support at least a portion of the
rotor blade. Thus, due to a shape of the rotor blade, when the
rotor blade is installed in the lifting device and lifted uptower,
the rotor blade can experience an asymmetric loading. Accordingly,
the lift system also includes a variable airflow assembly coupled
to tip end of the lifting device. The variable airflow assembly
includes at least one surface moveable between a plurality of
positions having varying resistances so as to counteract the
asymmetric loading.
[0010] In an embodiment, the plurality of positions may include, at
least, a first position and a second position. In an embodiment,
the surface(s) may be one of a plurality of surfaces mounted to a
frame member. In such embodiments, the first position may be
synonymous with the plurality of surfaces being in an open position
with respect to the frame member and the second position may be
synonymous with the plurality of surfaces being in a closed
position with respect to the frame member, wherein the open
position provides a first resistance with respect to the asymmetric
loading and the closed position provides a second resistance with
respect to the asymmetric loading. Further, in such embodiments,
the second resistance is greater than the first resistance.
[0011] In another embodiment, the surface(s) may be secured to a
hinge point. In such embodiments, the first position may be
synonymous with the surface(s) being in a compressed position and
the second position may be synonymous with the surface(s) being in
an expanded position from the hinge point, wherein the compressed
position provides a first resistance with respect to the asymmetric
loading and the expanded position provides a second resistance with
respect to the asymmetric loading. Further, in such embodiments,
the second resistance is greater than the first resistance.
[0012] In further embodiments, the variable airflow assembly may be
moveably coupled to tip end of the lifting device such that the
variable airflow assembly can be moved to a hidden position with
respect to the structural frame body to minimize an impact of the
variable airflow assembly after the rotor blade has been installed
uptower.
[0013] In additional embodiments, the lift system may also include
a gyroscope assembly having at least one gyroscope configured to
modify an orientation of the lifting device as the lifting device
is lifted or lowered to and from a hub mounted to a tower of the
wind turbine. In one embodiment, the gyroscope assembly may include
a plurality of gyroscopes, such as a first gyroscope and a second
gyroscope. In such embodiments, the first and second gyroscopes may
be coupled to at least one of the root and the tip ends of the
structural frame body, respectively, or at an intermediate location
along the structural frame body, such as the center of the
structural frame body.
[0014] In another embodiment, the lift system may also include a
drive mechanism for driving the variable airflow assembly and/or
the gyroscope assembly. For example, in an embodiment, the drive
mechanism may include a generator, an integrated motor, or a
separate motor.
[0015] In still another embodiment, the lift system may include a
controller configured to control the drive mechanism of the at
least one of the variable airflow assembly or the gyroscope
assembly. For example, in one embodiment, the controller may
include a remote control, a turbine controller of the wind turbine,
or a separate controller from the wind turbine. Moreover, in an
embodiment, the lift system may include one or more sensors
communicatively coupled to the controller for monitoring the
orientation of the lifting device as the lifting device is lifted
or lowered to and from the hub mounted to the tower. In such
embodiments, as an example, the sensor(s) may include Global
Positioning Sensor (GPS) sensors, accelerometers, smart sensors, or
the like as well as combinations thereof.
[0016] In another aspect, the present disclosure is directed to a
method for controlling orientation of a lifting device for a rotor
blade of a wind turbine as the lifting device is lifted or lowered
to and from a hub mounted to a tower of the wind turbine. The
method includes securing a variable airflow assembly to a tip end
of a structural frame body of the lifting device. The structural
frame body supports a root cradle and a tip cradle. The variable
airflow assembly includes at least one surface moveable between a
plurality of positions having varying resistances so as to
counteract an asymmetric loading of the lifting device. The method
also includes securing the rotor blade atop the root and tip
cradles of the lifting device. Further, the method includes lifting
or lowering the lifting device between a ground location and the
hub while altering between the plurality of positions of the
surface(s) to counteract the asymmetric loading.
[0017] It should be understood that the methods described herein
may further include any of the additional steps and/or features as
described herein. In addition, in an embodiment, securing the
variable airflow assembly to the tip end of the structural frame
body of the lifting device may include moveably securing the
variable airflow assembly to the tip end of the structural frame
body.
[0018] For example, in one embodiment, the method may include
moving the variable airflow assembly to a hidden position with
respect to the structural frame body to minimize an impact of the
variable airflow assembly after the rotor blade has been removed
from the lifting device. In certain embodiments, as an example,
moving the variable airflow assembly to the hidden position may
include folding the variable airflow assembly against the structure
frame body, sliding the variable airflow assembly towards a center
location of the structural frame body, compressing the variable
airflow assembly, or receiving the variable airflow assembly within
a recess of the structural frame body.
[0019] Moreover, in an embodiment, the method may include coupling
a gyroscope assembly having at least one gyroscope to the lifting
device and fine tuning the orientation of the lifting device as the
lifting device is installed onto the hub mounted to the tower of
the wind turbine.
[0020] In yet another embodiment, the method may include
automatically controlling, via a processor of a controller, at
least one of the variable airflow assembly or the gyroscope
assembly so as to modify the orientation of the lifting device as
the lifting device is lifted or lowered to and from the hub mounted
to the tower.
[0021] These and other features, aspects and advantages of the
present disclosure will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the disclosure and,
together with the description, serve to explain the principles of
the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] A full and enabling disclosure of the present disclosure,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures, in which:
[0023] FIG. 1 illustrates a perspective view of one embodiment of a
wind turbine according to the present disclosure;
[0024] FIG. 2 illustrates a side view of one embodiment of a rotor
blade according to the present disclosure;
[0025] FIG. 3 illustrates a perspective view of one embodiment of a
lift system according to the present disclosure;
[0026] FIG. 4 illustrates a perspective view of one embodiment of a
lifting device according to the present disclosure;
[0027] FIG. 5 illustrates a perspective view of one embodiment of a
gyroscope according to the present disclosure;
[0028] FIG. 6 illustrates a perspective view of one embodiment of a
lift system for a rotor blade of a wind turbine, particularly
illustrating first and second gyroscopes mounted at opposing ends
of a lifting device of the lift system;
[0029] FIG. 7 illustrates a schematic diagram of one embodiment of
a lift system for a rotor blade of a wind turbine, particularly
illustrating first and second gyroscopes mounted at opposing ends
of a lifting device of the lift system and having reversed tilt
angles;
[0030] FIG. 8 illustrates a perspective view of one embodiment of a
variable airflow assembly according to the present disclosure,
particularly illustrating a plurality of surfaces of the variable
airflow assembly in an open position;
[0031] FIG. 9 illustrates a perspective view of the variable
airflow assembly of FIG. 8, particularly illustrating the plurality
of surfaces of the variable airflow assembly in a closed
position;
[0032] FIG. 10 illustrates a perspective view of another embodiment
of a variable airflow assembly according to the present disclosure,
particularly illustrating a surface of the variable airflow
assembly in a compressed position;
[0033] FIG. 11 illustrates a perspective view of the variable
airflow assembly of FIG. 10, particularly illustrating the surface
of the variable airflow assembly in an expanded position;
[0034] FIGS. 12A and 12B illustrate schematic views of one
embodiment of the variable airflow assembly according to the
present disclosure, particularly illustrating the variable airflow
assembly in an active position and a hidden position,
respectively;
[0035] FIGS. 13A and 13B illustrate schematic views of another
embodiment of the variable airflow assembly according to the
present disclosure, particularly illustrating the variable airflow
assembly in an active position and a hidden position,
respectively;
[0036] FIG. 14 illustrates a simplified, block diagram of one
embodiment of suitable components that may be included in a
controller according to the present disclosure;
[0037] FIG. 15 illustrates a schematic diagram of one embodiment of
a failsafe mode of operation implemented by a controller of the
lift system according to the present disclosure;
[0038] FIG. 16 illustrates a schematic diagram of another
embodiment of a failsafe mode of operation implemented by a
controller of the lift system according to the present
disclosure;
[0039] FIG. 17 illustrates a schematic diagram of yet another
embodiment of a failsafe mode of operation implemented by a
controller of the lift system according to the present
disclosure;
[0040] FIG. 18 illustrates a schematic diagram of still another
embodiment of a failsafe mode of operation implemented by a
controller of the lift system according to the present disclosure;
and,
[0041] FIG. 19 illustrates a flow diagram of one embodiment of a
method for controlling orientation of a lifting device for a rotor
blade of a wind turbine as the lifting device is lifted or lowered
to and from a hub mounted to a tower of the wind turbine according
to the present disclosure.
DETAILED DESCRIPTION
[0042] Reference now will be made in detail to embodiments of the
disclosure, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
disclosure, not limitation of the disclosure. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present disclosure without departing
from the scope or spirit of the disclosure. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present disclosure covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0043] When lifting an asymmetrical load under a crane hook in an
open environment where wind is present, such load can develop a
torque and begin to rotate due to the wind-vane effect. An example
of such asymmetrical loading includes a wind turbine rotor blade
being lifted uptower. This effect is typically compensated by the
use of at least one tag line. As the rotor blade is lifted,
however, control of the load via the tag line(s) becomes less
effective. More specifically, the operator has to apply more and
more force to the tag line(s) as the load is lifted with less
results. In addition, due to the shape of the rotor blade (i.e. a
thick, round root end that tapers to a long, slender tip end), the
blade can experience asymmetric loading (e.g. due to the incoming
wind) as it is lifted uptower.
[0044] Generally, the present disclosure is directed to a lift
system for a wind turbine rotor blade and a method of controlling
the ascent and descent thereof with or without a rotor blade loaded
into it, without the aid of tag lines or tag line crews. More
specifically, the present disclosure is directed to a system and
method for eliminating this undesirable torque by creating a
compensating torque in the opposite direction by utilizing a
surface or vane that is variable in size and/or aerodynamic
resistance. Thus, by using surfaces which are variable in size
and/or aerodynamic resistance, a torque of equal but opposite
magnitude can be created to cancel out the undesirable rotation of
the lifting device, thus stabilizing the load on its way
uptower.
[0045] In addition, in one embodiment, the lift system of the
present disclosure is further equipped with a positioning control
device having of at least one gyroscope suspended in a gimbal mount
which allows for the creation of the forces created by the
gyroscopic precession to allow for a precise positioning of said
load. More particularly, utilizing the precessive forces allows the
load to be precisely positioned in order to facilitate the assembly
of the hoisted object to a supporting structure. As generally
understood, a gyroscope tends to maintain its position in space or
in other words, the axis, around which it is revolving, and tends
to resist changes in its orientation by outside influences.
Inversely, if an outside force causes a change in the position of
the axis, a reacting force in a plane perpendicular to that of the
outside force is being generated. Accordingly, the present
disclosure utilizes this gyroscopic behavior, which is also called
precession. For example, a pair of gyroscopes are configured to
spin in a vertical plane. More specifically, the gyroscopic wheels
are suspended in a way that they can be tilted around a horizontal
axis. If the gyroscopes are tilted in opposite directions, the
resulting precession forces create a torque which will cause the
lifting device to rotate. Further, a single force is exerted when
the gyroscope tilts that is related to the degree to which it is
tilted and the speed at which it tilts. Once this force has been
exerted, the system coasts to a stop, until the gyroscope is tilted
again when it exerts another force. Thus, by tilting the
gyroscopes, a more direct control over the load is achieved
compared to tag line input from a ground-based crew.
[0046] Referring now to the drawings, FIG. 1 illustrates a
perspective view of one embodiment of a wind turbine 10 according
to the present disclosure. As shown, the wind turbine 10 includes a
tower 12 with a nacelle 14 mounted thereon. A plurality of rotor
blades 16 are mounted to a rotor hub 18, such as via the roots
(discussed below) of the rotor blades, which is in turn connected
to a main flange that turns a main rotor shaft (not shown). The
wind turbine power generation and control components are typically
housed within the nacelle 14 and/or the tower 12. The view of FIG.
1 is provided for illustrative purposes only to place the present
disclosure in an exemplary field of use. It should be appreciated
that the disclosure is not limited to any particular type of wind
turbine configuration.
[0047] Referring now to FIG. 2, a perspective view of one of the
rotor blades 16 of FIG. 1 according to the present disclosure is
illustrated. As shown, the rotor blade 16 includes exterior
surfaces defining a pressure side 22 and a suction side 24
extending between a leading edge 26 and a trailing edge 28, and
extends from a blade tip 32 to a blade root 34. The exterior
surfaces may be generally aerodynamic surfaces having generally
aerodynamic contours, as is generally known in the art. In some
embodiments, the rotor blade 16 may include a plurality of
individual blade segments aligned in an end-to-end order from the
blade tip 32 to the blade root 34. Each of the individual blade
segments may be uniquely configured such that the plurality of
blade segments define a complete rotor blade 16 having a designed
aerodynamic profile, length, and other desired characteristics. For
example, each of the blade segments may have an aerodynamic profile
that corresponds to the aerodynamic profile of adjacent blade
segments. Thus, the aerodynamic profiles of the blade segments may
form a continuous aerodynamic profile of the rotor blade 16.
Alternatively, the rotor blade 16 may be formed as a singular,
unitary blade having the designed aerodynamic profile, length, and
other desired characteristics.
[0048] The rotor blade 16 may, in exemplary embodiments, be curved.
Curving of the rotor blade 16 may entail bending the rotor blade 16
in a generally flap-wise direction and/or in a generally edge-wise
direction. The flap-wise direction may generally be construed as
the direction (or the opposite direction) in which the aerodynamic
lift acts on the rotor blade 16. The edge-wise direction is
generally perpendicular to the flap-wise direction. Flap-wise
curvature of the rotor blade 16 is also known as pre-bend, while
edgewise curvature is also known as sweep. Thus, a curved rotor
blade 16 may be pre-bent and/or swept. Curving may enable the rotor
blade 16 to better withstand flapwise and edgewise loads during
operation of the wind turbine 10, and may further provide clearance
for the rotor blade 16 from the tower 12 during operation of the
wind turbine 10.
[0049] Still referring to FIG. 2, the rotor blade 16 may further
define chord 42 and a span 44. Further, as shown in FIG. 2, the
chord 42 may vary throughout the span 44 of the rotor blade 16.
Thus, a local chord may be defined for the rotor blade 16 at any
point on the rotor blade 16 along the span 44. The exterior
surfaces, as discussed above, may extend in the generally span-wise
direction between the tip 32 and root 34.
[0050] Referring now to FIGS. 3 through 7, various components of a
lift system 50 for a rotor blade 16 of a wind turbine 10 according
to the present disclosure are illustrated. As shown in FIGS. 3 and
4, the lift system 50 includes a lifting device 52 configured to
support at least a portion of the rotor blade 16. More
specifically, as shown, the lifting device 52 includes at least one
cradle 54, 56, which is described in more detail below. For
example, as shown, the lifting device 52 includes a root cradle 54
and a tip cradle 56 for supporting portions of the blade 16 near
the blade root 34 and the blade tip 32, respectively. Further, in
certain embodiments, each of the cradles 54, 56 generally has a
profile that corresponds to at least one of the exterior surfaces
of the rotor blade 16 so as to support at least a portion of the
rotor blade 16. For example, as shown in FIGS. 3 and 4, the root
cradle 54 has a profile that generally corresponds to the blade
root 34 of the rotor blade 16, whereas the tip cradle 56 has a
profile that generally corresponds to the blade tip 32 of the rotor
blade 16.
[0051] In addition, as shown in FIGS. 3 and 4, the lifting device
52 may include a structural frame body 55 for connecting and
supporting the root cradle 54 and the tip cradle 56. More
specifically, as shown, the structural frame body 55 may include
one or more cradle supports 57 configured to support each of the
root and tip cradles 54, 56, respectively. Thus, as shown, the root
and tip cradles 54, 56 may be mounted to respective ends of the
structural frame body 55, i.e. the root end 65 and the tip end 67
of the structural frame body 55, respectively. Further, the cradle
supports 57 may be joined or coupled together via a main support 59
or beam. Thus, in additional embodiments, the lift system 50 may
also include a crane (not shown) and a crane cable or sling 58
(FIGS. 3 and 4). In such embodiments, the crane may be coupled to
the cable or sling 58, which is secured to the structural frame
body 55 such that the crane can lift and/or lower the rotor blade
16 between the hub 18 and the tower 12. More specifically, the
crane cable or sling 58 may include a synthetic fabric sling and/or
a central attachment point so as to provide stability to the
lifting device 52 during lifting and/or lowering.
[0052] The crane as described herein may be any suitable machine
for generally lifting equipment and/or materials, such as a mobile
crane, a floating crane, an aerial crane, or a fixed crane (such as
a tower crane), as is generally known in the art. Further, the
crane cable or sling 58 may be connected to the crane, and the
crane may control movement of the crane cable or sling 58, as is
generally known in the art.
[0053] As shown particularly in FIG. 3, due to a shape of the rotor
blade 16, when the rotor blade 16 is installed in the lifting
device 52 and lifted uptower, the rotor blade 16 can experience
asymmetric loading. Thus, as shown in FIGS. 3-13B, the lift system
50 may also include a variable airflow assembly 100 coupled to tip
end 67 of the lifting device 52. The variable airflow assembly 100
includes at least one surface 102 operable between a plurality of
positions with varying resistances (i.e. varying aerodynamic drag
coefficients) so as to counteract the asymmetric loading. For
example, as shown in FIGS. 8-9 and 10-11, in an embodiment, the
plurality of positions may include, at least, a first position
(FIGS. 8, 10) and a second position (FIGS. 9, 11).
[0054] In addition, the surface(s) 102 of the variable airflow
assembly 100 described herein may have a variety of suitable
configurations. For example, in an embodiment, as shown in FIG. 8,
the variable airflow assembly 100 may include a plurality of
surfaces 102 mounted to a frame member 104. More particularly, as
shown in FIGS. 8 and 9, the surfaces 102 may be vanes or louvers.
Further, in such embodiments, as shown in FIG. 8, the first
position may be synonymous with the plurality of surfaces 102 being
in an open position with respect to the frame member 104. Further,
as shown in FIG. 9, the second position may be synonymous with the
plurality of surfaces 102 being in a closed position with respect
to the frame member 104. Thus, the open position provides a first
resistance with respect to the asymmetric loading, whereas the
closed position provides a second resistance with respect to the
asymmetric loading. In such embodiments, the second resistance is
greater than the first resistance.
[0055] In particular embodiments, the surface(s) 102 of the
variable airflow assembly 100 may similar to an HVAC louver system.
As such, in certain embodiments, the position of the louvers may be
controlled by various devices such as damper actuators, motors,
plungers, etc. More specifically, in certain embodiments, as shown
in FIG. 9, the louvers 104 can be controlled by a programmable
controller (PLC) 105 with an analog output, such as a 4-20 mA
output, or by a safety rated field bus, like CAN or ProfiNet. Thus,
in such embodiments, the surface(s) 102 of the variable airflow
assembly 100 can utilize a safety PLC with an output, either a
safety rated field bus or traditional analog output, to hold the
last known position of the louvers in the event power is lost or
the e-stop is engaged.
[0056] Referring now to FIGS. 10 and 11, in another embodiment, the
surface(s) 102 of the variable airflow assembly 100 may be
expandable from a hinge point 106. In such embodiments, as shown in
FIG. 10, the first position may be synonymous with the surface 102
being in a compressed position. Further, as shown in FIG. 11, the
second position may be synonymous with the surface 102 being in an
expanded position. Thus, the compressed position provides a first
resistance with respect to the asymmetric loading and the expanded
position provides a second resistance with respect to the
asymmetric loading. Further, in such embodiments, the second
resistance is greater than the first resistance.
[0057] In further embodiments, the variable airflow assembly 100
may be moveably coupled to tip end 67 of the lifting device 52 such
that the variable airflow assembly 100 can be moved to a hidden
position with respect to the structural frame body 55 to minimize
an impact of the variable airflow assembly 100 after the rotor
blade 16 has been removed from the lifting device 52 (e.g. after
the rotor blade 16 has been installed uptower). In certain
embodiments, as shown in FIGS. 12A and 12B, the variable airflow
assembly 100 may be moved to the hidden position by folding the
assembly 100 against the structure frame body 55, e.g. by rotating
the variable airflow assembly 100 about hinge point 108 such that
the variable airflow assembly 100 sits flush against the structural
frame body 55. Alternatively, as shown in FIG. 6, the variable
airflow assembly 100 may be moved to the hidden position by sliding
the variable airflow assembly 100, e.g. via a rail system 110,
towards a center location of the structural frame body 55. In still
another embodiment, as shown in FIGS. 10 and 11, the variable
airflow assembly 100 may be moved to the hidden position by
compressing the variable airflow assembly 100 from an expanded
position to a compressed position. In such embodiments, the
compressed surface assembly 100 may also then be folded against the
structural frame body 55. In yet another embodiment, as shown in
FIGS. 13A and 13B, the variable airflow assembly 100 may be moved
to the hidden position by receiving the variable airflow assembly
100 within a recess 112 of the structural frame body 55, i.e. when
the surface assembly 100 is no longer in use or needed.
[0058] Referring still to FIGS. 3-7, the lift system 50 may also
include a gyroscope assembly 60 having at least one gyroscope 62
coupled to the lifting device 52. As used herein, a gyroscope
generally refers to a device used for measuring or maintaining
orientation and angular velocity. More specifically, as shown in
FIG. 5, a perspective view of one embodiment of the gyroscope 62 is
illustrated. As shown, the illustrated gyroscope 62 includes a
spinning wheel 66 or disc that is mounted in a manner, such as a
fork mount, to allow for the rotation of the wheel 66 about an axis
of rotation 74 and about the axis of the fork. Thus, rotation of
the gyroscope 62 can be used to modify an orientation of the
lifting device 52 as the device 52 is lifted or lowered to and from
the hub 20 mounted uptower.
[0059] In further embodiments, the gyroscope assembly 60 may
include a plurality of gyroscopes 62, 64. For example, as shown
particularly in FIGS. 3-4 and 6-8, the gyroscope assembly 60 may
include a first gyroscope 62 and a second gyroscope 64. More
specifically, as shown in the illustrated embodiments, the first
and second gyroscopes 62, 64 may be coupled to opposing ends, i.e.
the root and tip ends 65, 67, of the structural frame body 55. It
should be understood that the first and second gyroscopes 62, 64
may be mounted to have any suitable mounting orientation. For
example, as shown, the first and second gyroscopes 62, 64 may be
mounted to extend generally parallel with the top beam of the
structural frame body 55. Alternatively, as shown in FIG. 4, the
first and second gyroscopes 62, 64 may be mounted to extend
generally perpendicular with the top beam of the structural frame
body 55. In yet another embodiment, the first and second gyroscopes
62, 64 may be mounted at any other orientation with respect to the
structural frame body 55. Furthermore, the first and second
gyroscopes 62, 64 may located at any suitable location along the
structural frame body 55. For example, as shown in FIG. 3, the
first and second gyroscopes 62, 64 may be spaced evenly from the
center location of the structural frame body 55 (e.g. as shown by
distance r). Alternatively, as shown in FIG. 4, the first and
second gyroscopes 62, 64 may be mounted at or towards the center
location of the structural frame body 55.
[0060] In additional embodiments, as shown in FIGS. 3 and 4, the
lift system 50 may include one or more drive mechanisms 80 for
driving the variable airflow assembly 100 and/or the gyroscope
assembly 60. For example, in certain embodiments, the drive
mechanism 80 may be a generator, an integrated motor, a separate
motor, or any other suitable power device. In one embodiment, for
example, the first and second gyroscopes 62, 64 may each be
controlled via a speed motor 63, 65 and/or a tilt motor 67, 69. In
such embodiments, where the first and second gyroscopes 62, 64 are
controlled by respective speed motors 63, 65 that can be controlled
by a speed-controlled drive, the speed-controlled drive can be
safety-rated by having safe speed shutdown definitions built
therein to pre-determined Safety Integrity Level (SIL) ratings. In
such embodiments, the safe speed generally refers to the maximum
speed of the gyroscope motors 63, 65. With the safety drive, the
safe speed may be equal to a certain percentage of the maximum
speed rating. If further embodiments, the motors 63, 65 do not have
to be controlled by the drive, but rather, the safe shutdown
mechanism can be achieved through a relay logic arrangement,
comparable to the drive SIL rating.
[0061] In further embodiments, the tilt motors 67, 69 may be
controlled by a position-controlled drive or servomotor. This
enables the drives to be safety rated and have safe position
shutdown definitions programmed therein. The safe position, for
example, can be the last position of the tilt motors 67, 69. Thus,
when power is lost or an emergency stop is engaged, the brakes of
the motors 67, 69 can be applied and the drive(s) holds the last
position. Again, the tilt motors 67, 69 do not necessarily have to
be controlled by the drive and the safe shutdown mechanism can
still be achieved through a relay logic arrangement, comparable to
the drive SIL rating.
[0062] Accordingly, as shown in FIG. 8-9 or 10-11, the drive
mechanism 80 described herein may be configured to move the
surfaces 102 of the variable airflow assembly 100 between the
plurality of positioned described herein. Furthermore, as shown in
FIGS. 6 and 7, the drive mechanism 80 may be configured to orient
the tilt angles/directions 76, 78 of the first and second
gyroscopes 62, 64 in opposing directions. Thus, as shown, the
lifting device 52 can be rotated about the single suspension point
(i.e. the crane hook), whereas reversing the tilt angle of the
first and second gyroscopes 62, 64 is configured to generate a
torque T (FIGS. 6 and 7) to stop and/or reverse the direction of
rotation of the lifting device 52.
[0063] In addition, as shown, the lift system 50 may further
include a controller 82 communicatively coupled with one or more
sensors 90, 92, e.g. for monitoring and controlling the drive
mechanism 80 of the variable airflow assembly 100 and/or the
gyroscope assembly 60 as well as the various motors described
herein. Moreover, in certain embodiments, the sensors 90, 92 may be
used to measure one or more wind conditions, such as wind speed
and/or wind direction. In such embodiments, the lift system 50 may
include, as an example, a GPS system on one or more ends of the
structural frame body 55 to detect motion and/or counteract said
motion as well as wind condition sensors. Thus, the controller 82
may be configured to utilize various inputs to determine how to
actuate the variable airflow assembly 100 and/or the gyroscope
assembly 60. By detecting the wind speed and/or wind direction, the
GPS system can quickly detect changes of the system 50 as the
system 50 is being raised and/or lowered.
[0064] The controller 82 as described herein may be incorporated
into a suitable control system of the wind turbine 10 (not shown),
a handheld remote, a personal digital assistant, cellular
telephone, a separate controller or computer having one or more
processor(s) and associated memory devices. Further, in particular
embodiments, as an example, the sensor(s) 90, 92 may include Global
Positioning Sensor (GPS) sensors, accelerometers, smart sensors, or
the like as well as combinations thereof. Accordingly, in
particular embodiments, the controller 82 may allow for a
Z-coordinate of the structural frame body 55 to change in a
vertical direction up to predetermined altitude or height while
maintaining an X-coordinate and a Y-coordinate of the structural
frame body 55 via the first and second gyroscopes 62, 64 as the
lifting device 52 is brought closer to the hub 18.
[0065] In another embodiment, the controller 82 may control the
lift system 50 by receiving a plurality of sensor signals from one
or more sensors 90, 92, respectively, and controlling the drive
mechanism 80 so as to alter a position of the surface(s) 102 and/or
gyroscopes 62, 64 based on the sensor signals. More specifically,
in one embodiment, the controller 82 may open or close the
surface(s) 102 and/or reverse the tilt angles of the first and
second gyroscopes 62, 64 to stop and/or reverse a direction of
rotation of the lifting device 52.
[0066] Further, as shown in FIG. 14, there is illustrated a block
diagram of one embodiment of various components of the controller
82 according to the present disclosure. As shown, the controller 82
may include one or more processor(s) 83 and associated memory
device(s) 85 configured to perform a variety of
computer-implemented functions (e.g., performing the methods,
steps, calculations and the like and storing relevant data as
disclosed herein). Additionally, the controller 82 may also include
a communications module 87 to facilitate communications between the
controller 82 and the various components of the variable airflow
assembly 100 and/or the gyroscope assembly 60. Further, the
communications module 87 may include a sensor interface 89 (e.g.,
one or more analog-to-digital converters) to permit signals
transmitted from the sensors 90, 92 to be converted into signals
that can be understood and processed by the processors 83. It
should be appreciated that the sensors 90, 92 may be
communicatively coupled to the communications module 87 using any
suitable means. For example, as shown in FIG. 14, the sensors 90,
92 are coupled to the sensor interface 89 via a wired connection.
However, in other embodiments, the sensors 90, 92 may be coupled to
the sensor interface 89 via a wireless connection, such as by using
any suitable wireless communications protocol known in the art.
[0067] As used herein, the term "processor" refers not only to
integrated circuits referred to in the art as being included in a
computer, but also refers to a controller, a microcontroller, a
microcomputer, a programmable logic controller (PLC), an
application specific integrated circuit, and other programmable
circuits. Additionally, the memory device(s) 85 may generally
comprise memory element(s) including, but not limited to, computer
readable medium (e.g., random access memory (RAM)), computer
readable non-volatile medium (e.g., a flash memory), a floppy disk,
a compact disc-read only memory (CD-ROM), a magneto-optical disk
(MOD), a digital versatile disc (DVD) and/or other suitable memory
elements. Such memory device(s) 85 may generally be configured to
store suitable computer-readable instructions that, when
implemented by the processor(s) 58, configure the controller 82 to
perform various functions.
[0068] In further embodiments, upon engagement of an emergency stop
or power loss, the controller 82 is also configured to operate in a
failsafe mode. For example, in such embodiments, the failsafe mode
may include maintaining the gyroscope motors at a maximum speed,
maintaining the gyroscope tilt motors at the last known position
and/or maintaining the louvers at the last known position. In
particular, as shown in FIG. 15, a schematic diagram of one
embodiment of a failsafe mode or safe shutdown procedure
implemented by the controller 82 is illustrated. As shown, FIG. 15
generally illustrates the initiation of the failsafe mode, in which
the controller 82 is communicatively coupled to a motor 122 or
converter 124 of the system. Further, as shown, the system may also
include one or more batteries 126. Thus, as shown the controller 82
is configured to control an automatic transfer switch 120 to
initiate an emergency stop 114. The emergency stop 114 can thus
engage a safety relay 116 (e.g. during the power loss) and a reset
118 (e.g. when power is restored).
[0069] Referring now to FIG. 16, the failsafe mode of the
controller 82 may also include holding the louvers 102 to their
last known positions. For example, as shown, upon engagement of an
emergency stop or power loss, the controller 82 may be configured
to receive signals 128 associated with the last known position of
each of the louvers 102. Thus, the controller 82 can actuate and/or
hold, e.g. via a plurality of actuators, the last known position of
each of the louvers until the power loss is restored.
[0070] Referring now to FIG. 17, the failsafe mode of the
controller 82 may also include maintaining a speed of the
gyroscopic motors 63, 65 to a pre-determined speed. Similarly, as
shown in FIG. 18, the failsafe mode of the controller 82 may also
maintaining an angle of the first and second gyroscopes via the
tilt motors 67, 69, e.g. at the last known position.
[0071] Referring now to FIG. 19, a flow diagram of one embodiment
of a method 100 for controlling orientation of a lifting device for
a rotor blade of a wind turbine as the lifting device is lifted or
lowered to and from a hub mounted to a tower of the wind turbine is
illustrated. In general, the method 200 will be described herein
with reference to the wind turbine 10 and lift system 50 shown in
FIGS. 1-18. However, it should be appreciated that the disclosed
method 200 may be implemented with wind turbines having any other
suitable configurations. In addition, although FIG. 19 depicts
steps performed in a particular order for purposes of illustration
and discussion, the methods discussed herein are not limited to any
particular order or arrangement. One skilled in the art, using the
disclosures provided herein, will appreciate that various steps of
the methods disclosed herein can be omitted, rearranged, combined,
and/or adapted in various ways without deviating from the scope of
the present disclosure.
[0072] As shown at (202), the method 200 may include securing the
variable airflow assembly 100 to the tip end 67 of the structural
frame body 55 of the lifting device 52. As mentioned, the
structural frame body 55 supports the root cradle 54 and the tip
cradle 56. Further, as mentioned, the variable airflow assembly 100
includes at least one surface 102 operable between a plurality of
positions with varying resistances so as to counteract an
asymmetric loading of the lifting device 52. In an embodiment, for
example, the variable airflow assembly 100 may be moveably secured
to the tip end 67 of the structural frame body 55 of the lifting
device 52. As shown at (204), the method 200 also includes securing
the rotor blade 16 atop the root and tip cradles 54, 56 of the
lifting device 52. In alternative embodiments, it should be
understood that the lifting device 52 may also be lifted or lowered
to and from the hub without the rotor blade 16 installed therein.
As shown at (206), the method 200 may include lifting or lowering
the lifting device 52 between a ground location and the hub 18
while altering between the plurality of positions of the surface(s)
102 to counteract the asymmetric loading.
[0073] In certain embodiments, once the rotor blade 16 is removed
from the lifting device 52, the method 200 may also include moving
the variable airflow assembly 100 to a hidden position with respect
to the structural frame body 55, i.e. to minimize an aerodynamic
impact of the variable airflow assembly 100. In certain
embodiments, as an example, the method 200 may include folding the
variable airflow assembly 100 against the structure frame body 55.
Moreover, in an embodiment, the method 200 may include sliding the
variable airflow assembly 100 towards a center location of the
structural frame body 55. In yet another embodiment, the method 200
may include compressing the variable airflow assembly 100. In
additional embodiments, the method 200 may include receiving the
variable airflow assembly 100 within a recess of the structural
frame body 55.
[0074] Further aspects of the invention are provided by the subject
matter of the following clauses:
[0075] Clause 1. A lift system for a rotor blade of a wind turbine,
the lift system comprising:
[0076] a lifting device comprising a structural frame body having a
root end and a tip end, the root end supporting a root cradle, the
tip end supporting a tip cradle, the root and tip cradles each
comprising a profile that corresponds to at least one exterior
surface of the rotor blade so as to receive and support at least a
portion of the rotor blade, wherein, when the rotor blade is
installed in the lifting device and lifted uptower, the rotor blade
experiences an asymmetric loading; and,
[0077] a variable airflow assembly coupled to tip end of the
lifting device, the variable airflow assembly comprising at least
one surface moveable between a plurality of positions having
varying resistances so as to counteract the asymmetric loading.
[0078] Clause 2. The lift system of clause 1, wherein the plurality
of positions comprise, at least, a first position and a second
position.
[0079] Clause 3. The lift system of clause 2, wherein the at least
one surface is one of a plurality of surfaces mounted to a frame
member, the first position being synonymous with the plurality of
surfaces being in an open position with respect to the frame member
and the second position being synonymous with the plurality of
surfaces being in a closed position with respect to the frame
member, wherein the open position provides a first resistance with
respect to the asymmetric loading and the closed position provides
a second resistance with respect to the asymmetric loading, the
second resistance being greater than the first resistance.
[0080] Clause 4. The lift system of clause 2, wherein the at least
one surface is secured to a hinge point, the first position being
synonymous with the at least one surface being in a compressed
position and the second position being synonymous with the at least
one surface being in an expanded position from the hinge point,
wherein the compressed position provides a first resistance with
respect to the asymmetric loading and the expanded position
provides a second resistance with respect to the asymmetric
loading, the second resistance being greater than the first
resistance.
[0081] Clause 5. The lift system of any of the preceding clauses,
wherein the variable airflow assembly is moveably coupled to tip
end of the lifting device such that the variable airflow assembly
can be moved to a hidden position with respect to the structural
frame body to minimize an impact of the variable airflow assembly
after the rotor blade has been installed uptower.
[0082] Clause 6. The lift system of any of the preceding clauses,
further comprising a gyroscope assembly comprising at least one
gyroscope configured to modify an orientation of the lifting device
as the lifting device is lifted or lowered to and from a hub
mounted to a tower of the wind turbine.
[0083] Clause 7. The lift system of clause 6, wherein the at least
one gyroscope comprises a first gyroscope and a second gyroscope,
the first and second gyroscopes being coupled at least one of the
root and the tip ends of the structural frame body, respectively,
or at an intermediate location along the structural frame body.
[0084] Clause 8. The lift system of clause 6, further comprising a
drive mechanism for driving at least one of the variable airflow
assembly or the gyroscope assembly, the drive mechanism comprising
at least one of a generator, an integrated motor, or a separate
motor.
[0085] Clause 9. The lift system of clause 8, further comprising a
controller configured to control the drive mechanism of the at
least one of the variable airflow assembly or the gyroscope
assembly.
[0086] Clause 10. The lift system of clause 8, wherein, when power
is lost or an emergency stop is initiated, the controller is
configured to operate in a failsafe mode in which at least one of a
speed of the at least one gyroscope, a tilt of the at least one
gyroscope, or a position of the surface are controlled to a
predetermined safety threshold.
[0087] Clause 11. The lift system of clause 9, wherein the
controller comprises at least one of a remote control, a turbine
controller of the wind turbine, or a separate controller from the
wind turbine.
[0088] Clause 12. The lift system of clause 9, further comprising
one or more sensors communicatively coupled to the controller for
monitoring the orientation of the lifting device as the lifting
device is lifted or lowered to and from the hub mounted to the
tower, wherein the one or more sensors comprise at least one of
Global Positioning Sensor (GPS) sensors, accelerometers, smart
sensors, or combinations thereof.
[0089] Clause 13. A method for controlling orientation of a lifting
device for a rotor blade of a wind turbine as the lifting device is
lifted or lowered to and from a hub mounted to a tower of the wind
turbine, the method comprising:
[0090] securing a variable airflow assembly to a tip end of a
structural frame body of the lifting device, the structural frame
body supporting a root cradle and a tip cradle, the variable
airflow assembly comprising at least one surface operable between a
plurality of positions with varying resistances so as to counteract
an asymmetric loading of the lifting device;
[0091] securing the rotor blade atop the root and tip cradles of
the lifting device; and, lifting or lowering the lifting device
between a ground location and the hub while altering between the
plurality of positions of the at least one surface to counteract
the asymmetric loading.
[0092] Clause 14. The method of clause 13, wherein the at least one
surface is one of a plurality of surfaces mounted to a frame
member, the first position being synonymous with the plurality of
surfaces being in an open position with respect to the frame member
and the second position being synonymous with the plurality of
surfaces being in a closed position with respect to the frame
member, wherein the open position provides a first resistance with
respect to the asymmetric loading and the closed position provides
a second resistance with respect to the asymmetric loading, the
second resistance being greater than the first resistance.
[0093] Clause 15. The method of clauses 13-14, wherein the at least
one surface is secured to a hinge point, the first position being
synonymous with the at least one surface being in a compressed
position and the second position being synonymous with the at least
one surface being in an expanded position from the hinge point,
wherein the compressed position provides a first resistance with
respect to the asymmetric loading and the expanded position
provides a second resistance with respect to the asymmetric
loading, the second resistance being greater than the first
resistance.
[0094] Clause 16. The method of clauses 13-15, further comprising
moving the variable airflow assembly to a hidden position with
respect to the structural frame body to minimize an impact of the
variable airflow assembly after the rotor blade has been removed
from the lifting device.
[0095] Clause 17. The method of clauses 16, wherein moving the
variable airflow assembly to the hidden position comprises at least
one of folding the variable airflow assembly against the structure
frame body, sliding the variable airflow assembly towards a center
location of the structural frame body, compressing the variable
airflow assembly, or receiving the variable airflow assembly within
a recess of the structural frame body.
[0096] Clause 18. The method of clauses 13-17, further
comprising:
[0097] coupling a gyroscope assembly having at least one gyroscope
to the lifting device; and,
[0098] fine tuning the orientation of the lifting device as the
lifting device is installed onto the hub mounted to the tower of
the wind turbine.
[0099] Clause 19. The method of clauses 13-18, further comprising
automatically controlling, via a processor of a controller, at
least one of the variable airflow assembly or the gyroscope
assembly so as to modify the orientation of the lifting device as
the lifting device is lifted or lowered to and from the hub mounted
to the tower.
[0100] Clause 20. The method of clauses 13-19, wherein, when power
is lost or an emergency stop is initiated, operating, via the
controller, at least one of the variable airflow assembly or the
gyroscope assembly in a failsafe mode in which at least one of a
speed of the at least one gyroscope, a tilt of the at least one
gyroscope, or a position of the surface are controlled to a
predetermined safety threshold.
[0101] This written description uses examples to disclose the
disclosure, including the best mode, and also to enable any person
skilled in the art to practice the disclosure, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the disclosure is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *